That is a question I also want an answer on. G3 had stutters on my side when I wanted to replay it with CP1.75, but never got deeply into it (was distracted by some other game release and in the end didn't replay it).
But IIRC when I was searching for an answer, the catch/solution was to mess with the process priorities, not touching the engine resources. The stutters may not be visible from the start, but become obvious when you rotate the camera anywhere outside the first village.

In any case, I think it's high time to replay it instead of leaving it rotting on my PC… Putting it on top of my next to replay list.

I never understood why this 'momentary' stuttering is any problem in G3. It only stutters for a second or two when you enter a larger area of the map or teleport, and that's it - just a second or two, not continuous.

It did not detract from my enjoyment of this wonderful piece of gaming at all.

I am currently playing call of pripayt and it also slightly suffers from this stuttering once you enter the map.

As JDR said, if it was possible to do, someone would have done it. In fact, all open world developers would have implemented this 'magic technique' if it existed (without the need for loading when entering new game areas).